I have deleted the code extension="/usr/lib64/php/modules/phalcon.so" from php.ini
and created a file "phalcon.ini" inside the directory /etc/php.d/
the contents of the phalcon.ini is : echo "extension=phalcon.so">>/etc/php.d/phalcon.ini
Then I restarted the php-fpm use command "service php-fpm restart" and "service nginx restart"
The Warning message did not display again.